The present invention relates to a method and apparatus for extracting cellulosic fibers from a bale containing waste papers, which contains, a mixture of cellulosic fibers, contaminated cellulosic fibers, and separated or freely dispersed contaminants.
The term contaminants, as used herein, means materials of a non-cellulose fiber character, such as wax, polymer coatings, foil coatings, inks, dirt, stones, etc. The present invention has wide applicability in the recycling of paper products, for reuse in making paper.
In existing processes for making paper it is a common practice to use waste paper materials, either alone, or along with virgin pulp. The waste paper materials, recycled back into the papermaking method, commonly include, e.g. rejected paper stock in the plant, old corrugated containers, paper bags, newspapers, magazines, used paper containers of various types, office waste, mixed waste and old files. Some of these waste paper materials, have coatings thereon that interfere with normal papermaking operations, e.g. wax coatings, impregnated wax, various plastic coatings, and aluminum foil coatings. Dirt, paper clips, wires, some inks, and other contaminants, associated with waste papers, may also pose a problem.
Before the waste paper can be used in the manufacture of new paper, the cellulosic fiber content of the waste paper should preferably be separated from the contaminants. The separation method should be carried out in such a fashion, so as to minimize degradation or damage to the cellulosic fibers, e.g., by cutting, shortening or weakening such fibers.
It is known to recycle waste paper products by mechanically breaking or tearing apart such products in a pulper. However, such action damages, and adversely changes, the physical characteristics of the fibers. Also, the pulper does not always completely separate contaminants from the cellulosic fibers. Another disadvantage is the fact that considerable energy is required to effect a desired separating action.